Prior systems have sought to provide structures for accommodation training, brainwave training, electromyography training, and dichotic learning through ABW training with a subject's eyes closed. Such systems seek to, for example, reduce nervous tension, decrease reaction time, and otherwise improve physical or athletic performance by training a person to enter an ABW state. Initial ABW training systems required the subject's eyes to be closed, based on the general belief that a person could not enter the ABW state with open eyes. The inventor previously discovered that this belief was in error, and that an ABW state could be achieved with the eyes open and directed to a visual image.
The prior systems have taken advantage of the discovery that accommodation training is an efficient way to accomplish ABW training. In general, accommodation training uses biofeedback to train a patient to improve his or her visual focusing ability. In a typical device, the refraction of the eye is measured and used to produce auditory feedback such as a tone to which the patient may listen. The patient is then trained to be able to control eye focus based on the change in the auditory feedback that is produced as a result of changes in the refraction of the eye. This sort of training program is sometimes known by the general term “accommodation training” Because of the relationship between accommodation training and entry into an ABW state, accommodation training further teaches patients how to enter an ABW state.
An exemplary prior implementation of a system for such training with the subject's eyes open is described in U.S. Pat. No. 5,374,193 by the present inventor, the contents of which are incorporated by reference. The exemplary system was incorporated into a table or stand, thereby requiring the use of a head and chin support or an ophthalmic headband and articulated arm, either of which would seek to hold the patient's head in a fixed position with respect to the table on which the optical system is mounted. While the system was able to allow patients to enter an ABW state, and otherwise engage in accommodation training, the overall system was bulky, awkward for the patient to use, and subject to small head movements. The prior system was also not portable in any realistic sense, requiring patients to travel to a dedicated facility in order to participate in accommodation training.
Additional patents, such as U.S. Pat. Nos. 4,162,828, 4,533,221, 4,660,945, and 5,002,384, measure functions of the eye, such as ocular accommodation and eye position. These references have utilized a system of lenses, mirrors, beam splitters, and double slits. While such prior systems may provide various advantages, they all carry the common disadvantage of requiring a large, bulky, heavy, cumbersome structure that was affected by small head movements.